Constant pressure, variable volume delivery pump



1964 G. L. PYRITZ 3,143,076

CONSTANT PRESSURE}, VARIABLE VOLUME DELIVERY PUMP Filed 0ct.'ll, 1962 15 Sheets-Sheet 2 IFI 5'." 2A 93 94 39 97 I00 40 as wum HNVENTEIR I ,Q \27 GEORGE L. PYRITZ lFlEz-IZA WQ.

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CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed Oct. 11, 1962 13 Sheets-Sheet 3 HNVENTUR ///////7.\\\\\\\\\\\ EEEIREE PYRITZ MQ m ATTDRNEY Aug. 4, 1964 R G. L. PYYRITZ CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed 001;. 11, 1962 E EL- 6 n H5 H2. IF! E-. 5

13 Sheets-Sheet 4 HNVENTU GEORGE L. P

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1964 G. PYRITZ 3,143,076

CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed Oct. 11, 1962 13 Shets-Sheet e I 0% m an F E M k LQ 5 2 Bk 3 IIH d g m o g m 6 v 2. :3 P I L11 '3 t l o m a 3 3 I? L g k g m I II p 5! 3| I '5 a I m g :3 g e- Q m a F f;

F 1 H g r h 1 O 1' m E la I R w HNvENTEm Q m EEUREE L. PYR'ITZ WQW ATTEIRN EY 1964 G. PYRITZ 3,143,076

CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed Oct. 11, 1962 13 Sheets-Sheet '7 L \5'2. IFI 5:25

HNVENTEIR EEEIRE'IE L. PYRITZ MQM ATTIJRNEY 4, 1964 G. L. PYRITZ 3,143,076

CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed 00 11, 1962 13 Sheets-Sheet a ENTEIR ErEE IR L. PYRITZ W 4 m ATTORNEY Aug. 4, 1964 G. L. PYRITZ 3,143,076

CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed 001. 11, 1962 1s Sheets-Sheet 9 am A a y Arr UR NEV TUR 13 Sheets-Sheet l0 HNVENTLTR BEUREE 1.. PYRITZ a M ATTORNEY G. L. PYRITZ Aug. 4, 1964 CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed Oct. 11, 1962 IFI 5723 Aug. 4, 1964 G. L. PYRITZ I 3,143,076

CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed 001.. 11, 1962 13 Sheets-Sheet 11 JINVENTQR BED E-E L. PYRITZ AYMQM ATTORNEY 1964 G. PYRITZ 3,143,076

CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP Filed Oct. 11, 1962 13 Sheets-Sheet 12 l WQW m I v HNVENTU BEDREE EYRITZ v JYWQW ATTUR EY Aug. 4, 1964 e. PYRITZ 3,143,076

CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP 15 Sheets-Sheet 13 Filed Oct. 11, 1962 vvvvvvvwm"Mn?7mvmm5mm t? mm 2 l1 Q. I X m H. R h R V 2. n P In. 8 mm :MA N A a fifiafififi w I "4 .''A ill I m r v E NE m ||||.|ll.. 2 N v. 3 mm. mm 2. *R E E E 5. mm on. 5 z l I Q. 21 3 =3 E m in m 2, N2 ll|.l Tm I m H N.@ MP1 mt Q2 mm mmmm v wt 8 oh b United States Patent 3,143,076 CONSTANT PRESSURE, VARIABLE VOLUME DELIVERY PUMP George L. Pyritz, 55 S. Linwood Ave., Indianapolis 11, Ind. Filed Oct. 11, 1962, Ser. No. 230,009 8 Claims. (Cl. 103-37) This invention relates to a constant pressure, variable volume discharge pump particularly of high pressure discharge. By high pressure discharge is meant pressures on the order of two thousand pounds per square inch.

This particular type of pump finds usage in one instance for heavy duty power steering of vehicles such as trucks or truck tractors. It is conceivable that such a pump may be employed also in servo-mechanisms and hydraulic controls.

This invention may be incorporated in a variety of designs and is herein shown and described in a multiple, reciprocating piston construction wherein there is a port sleeve, automatically shiftable, determining the output volume while maintaining a constant pressure, and permitting a reduction in power input upon reduced volume output.

A primary purpose of the invention is, as above indicated, to provide a pump structure which will automatically maintain a substantially constant high pressure output with a volume discharge varying in accordance with demands.

A further important purpose of the invention is to provide a structure which will incorporate the minimum number of parts in a compact unit reasonably low in weight and size.

A still further important purpose is to provide a mechanism which is fool proof in respect to being self-contained and requiring no outside adjusting and regulatory devices affecting the pump operation.

A still further important purpose of the invention is to provide a mechanism requiring less power input for less volume output while maintaining a designed substantially constant discharge pressure under variable volume output flows.

These and many other purposes and objects, including the unique design and operation and functioning of the moving parts one in relation with the other, will become apparent to those versed in the art in the following description of one form of the invention and a variant thereof as illustrated in the accompanying drawings, in which FIG. 1 is a pump intake end elevational View;

FIG. 2 is a longitudinal section on the line 2-2 in FIG. 1;

FIG. 2A is a left hand pump portion in longitudinal section and side elevation locating the pressure high limit valve on the line 2A-2A in FIG. 1;

FIG. 3 is a transverse section on the line 3-3 in FIG. 2;

FIG. 4 is a transverse section on the line 4-4 in FIG. 2;

FIG. 5 is a transverse section on the line 5-5 in FIG. 2;

FIG. 6 is a transverse section on the line 6-6;

FIG. 7 is a drive end elevational view;

FIG. 8 is a side view on a slightly reduced scale of the drive shaft rotated 180 degrees from its position shown in FIG. 2;

FIG. 9 is a transverse section on the line 9-9 in FIG. 8;

FIG. 10 is a detail on an enlarged scale in partial section showing in side elevation the shiftable port sleeve rotated clockwise in the direction of the arrow, degrees from its position shown in FIG. 2;

FIG. 11 is a detail on an enlarged scale in partial section showing in side elevation the shiftable port sleeve rotated in the direction of the arrow degrees from its position in FIG. 2;

FIG. 12 is a detail on an enlarged scale in partial section showing in side elevation the shiftable port sleeve rotated in the direction of the arrow, 270 degrees from its position in FIG. 2;

FIG. 12A is a developed plan of the port sleeve;

FIG. 13 is a side view of a piston drive cam modified from that shown in FIGS. 2 and 8;

FIG. 14 is a reverse side View of the cam shown in FIG. 13;

FIG. 15 is a transverse section on a reduced scale on the line 15-15 in FIG. 12;

FIG. 16 is a View in partial section and a side elevational view of a modified form of a port sleeve required for use in connection with the cam shown in FIGS. 13 and 14;

FIG. 17 is a similar view of the modified port sleeve rotated clockwise 90 degrees from the position shown in FIG. 16;

FIG. 18 is a similar view of the modified port sleeve rotated 180 degrees clockwise from that position shown in FIG. 16;

FIG. 19 is a similar view of the modified port sleeve of FIG. 16 rotated 270 degrees clockwise from the position therein.

FIG. 20 is a transverse section on the line 20-20 in FIG. 16;

FIG. 21 is an intake or left hand end elevational view of a modified form of pump;

FIG. 22 is a view in longitudinal section on the line 22-22 in FIG. 21;

FIG. 23 is a view in longitudinal section on the line 23-23 in FIG. 21 of the left hand end pump portion;

FIG. 24 is a detail in section on the line 24-24 in FIG. 23;

FIG. 25 is a transverse sectional view on the line 25-25 in FIG. 22;

FIG. 26 is a transverse sectional view on the line 26-26 in FIG. 22

FIG. 27 is a transverse sectional view on the line 27-27 in FIG. 22;

FIG. 28 is a right hand end elevational view of the modified form of pump;

FIG. 29 is a view in top plan of the port sleeve of the modified pump form;

FIG. 30 is a right hand end elevational view of the port sleeve shown in FIG. 29;

FIG. 31 is a side elevational view of the port sleeve of FIG. 22 rotated clockwise in viewing the right hand and of the shaft 167 90 degrees from its position in FIGS. 22 and 29;

FIG. 32 is a side elevational view of the port sleeve of FIG. 22 rotated clockwise 180 degrees from its position in FIGS. 22 and 29;

FIG. 33 is a side elevational view of the port sleeve of FIG. 22 rotated clockwise 270 degrees from its position in FIGS. 22 and 29;

FIG. 34 is a side elevational view of the drive shaft shown in FIG. 22 rotated 180 degrees from its position shown therein; and

FIG. 35 is a transverse section on the line 35-35 in FIG. 34.

Referring first to that form of the invention as illustrated in FIGS. 1-15, a body generally designated by the numeral 4t) has a longitudinal bore 41 therethrough. A hearing 42 is fitted inaa counterbore 43 at the body intake 3 end 44. A sleeve 45 is fixed Within the bore 41 to extend a short distance along the bore 41.

The body 40 has an enlarged opposite end portion 46 which is designated as the drive end. The end portion 46 carries a cylindrical cup 47 opening out from the body 48 drive end and also oppositely opening into the body bore 41 through a counterbore 48. A sleeve 49 is fixed in the bore 41, extending from the counterbore 48 for a distance toward but terminating short of the sleeve 45.

A cylinder block 50 is fitted into the cup 47 and circumferentially fixed therein by any suitable means such as by one or more locating pins 51. This block 58 has a longitudinal bore 52 therethrough, axially aligned with the body bore 41, and carries a sleeve 53 fixed therein with an internal diameter in the present showing substantially equal to the internal diameters of the sleeves 45 and 49, the sleeves 45 and 59 have common internal diameters. Also, in the present showing, the block 58 is provided with a counterbore 54 opposing the counterbore 48, these two counterbores defining a chamber 55.

A drive shaft generally designated by the numeral 56 longitudinally extends in spaced relation through the sleeves 45, 49 and 53 and has an intake end portion 57 rotatably supported by the bearing 42. This portion 57 terminates approximately at the body end 44. There is a bush-ing 58 surrounding and fixed to the shaft 56 intermediate it and the bearing 42. The shaft 56 has a constant diameter from its end 57 to the chamber 55, into which chamber the shaft 56 enlarges into a hub 59. A cam 60 extends diagonally around the hub 59. The shaft 56 extends from the hub 59 by a larger diameter length 61 with a running fit through the sleeve 53 and beyond it and the body end portion 46 to a shoulder 62, from which shoulder the shaft extends by a reduced diameter length 63 as the drive end. This reduced length 63 is carried by a bearing 64.

A bore 65 extends from an opening from the shaft end 57, through the shaft 56 to at least a zone 66 which is within the sleeve 53. The shaft 56 has on one side a transverse slot 67 in communication with the shaft bore 65 through a hole 68. A slot 69 extends across the opposite side of the shaft 56 without communication with the bore 65. The shaft has a longitudinally extending port 70 opening from the bore 65 and located to be within the sleeve 49.

A port sleeve 71 is slidably mounted on the shaft 56 on that side of the hub 59 toward the intake end 57, and is held against revolution about the shaft 56 by a key or pin 72 entered in "a longitudinal keyway 73. A collar 74 integrally surrounds the port sleeve 71 and revolubly bears against the wall of the body bore 41.

A constant diameter skirt 75 extends longitudinally from lone side of the collar 74 concentrically of the shaft 56 and enters within the sleeve 45, terminating therein by an end 76 normally spaced from the bushing 58. The port sleeve 71 extends from the collar 74 with a running fit into the sleeve 49 and has lands and an opening therethrough which will later be described in setting forth the operation. A compression spring 77 surrounds the shaft 56 and extends within the skirt 75 to bear by opposite ends against the bushing 58 and the collar 74. This spring 77 normally tends to urge the port sleeve 71 along the shaft 56 to abut it against the hub 59.

The body 40 has a longitudinal passageway 78 leading from the end 46 and opening into a transversely extending chamber 79 which extends circumferentailly around and opens into the bore 41 at the end of the sleeve 49 removed from the chamber 55. This passageway 78 is on the drive end side of the collar 74. A second chamber 80, a discharge chamber, is provided adjacent the chamber 79 and is separated therefrom by a partition 81 above the bore 41, and extends downwardly to surround the skirt 75 at the end of the sleeve 45 directed toward the sleeve 49. The collar '74 seals 011 one chamber 79 from the other chamber 80 below the partition 81. An

4 externally discharging nipple a opens from the chamber 88.

A valve 82 seats against a seat 83 of a port 84 in the partition 81. Stems 85 and 86 extend from opposite sides of the valve 82. The stem 85 is slidingly received in a bore 87 in the body 40. The stem 86 extends across the passageway 88 and slidingly and sealably enters a sleeve 88 fixed in the body 40. The sleeve 88 opens through the body end 44 through an opening 89. A compressing spring 98 carried within the sleeve 88 bears by one end against a sleeve shoulder 91 and enters by the other end to within the stem 86 urging the valve 82 to its seated position. The valve 82 has a small, longitudinal slot 85a thereacross allowing a restricted flow of fluid between chambers 79 and 8%). An axial bore 85a extends through the valve 82 and stems 85, 86 to discharge into the sleeve 88 to prevent build up of pressure across the end of the stem 85 in the bore 87.

A pressure limit or relief valve 92, spaced circumferent-ially around in the body 40, FIGS. 1, 2A and 3, seats under the influence of a spring 93 against the end of a sleeve 94 fixed in the body and opening at the end opposite the valve 92 through the body end 44. A passageway 95 leads from the chamber 79 into a valve chamber 96. A valve stem 97 enters a'body bore 98 and has therearound a guide collar 99 slidingly guided in a counterbore 188, within which is the spring 93 hearing against the collar 99. A small, longitudinal slot 99a extends across the collar 99 permitting pressure to build up in the counterbore 188 to reduce the pressure required of spring 93 to keep the valve 92 seated. An axial bore 99c conducts :any leakage oil from the bore 98 to: a passageway 164.

An intake end cap 181 is sealably and removably secured to the body 40. The cap 101 has an intake bore 182 coaxially aligned with the shaft 56, and also a passageway 183 leading from the sleeve opening 80 to the cap bore 182. The cap 101 has the second passageway 104 leading from the sleeve 94 to the body intake bore 102.

A body, drive end cap 185 is sealably and removably secured to the body end 46. It carries the bearing 64. The cap 105 has an annular chamber 186 centered about the shaft 56, into which chamber the slot 69 of the shaft extends. A passageway 187 leads from the chamber 106 opening into the body passageway 78. An oil gathering groove 188 in the cap around the shaft 56 communicates with a return flow passageway 109 draining into the shaft bore 65.

The body 48 has a plurality of longitudinally extending cylinders 119, herein shown as nine in number, equally spaced apart and each centered on a common circle centered on the axis of the shaft 56. All of these cylinders open by common ends respectively into radial passages 111, one for each cylinder. Each of these passages 111 are ported through the sleeve 49 as at 112. The opposite ends of these cylinders 118 open into the chamber 55.

The cylinder block 50 has an equal number (nine) of cylinders 113 of the same diameter as that of the cylinders 110, longitudinally extending through it and axially aligned with the cylinders 118. The drive end cap 185 closes off the exposed ends of the cylinders 113. Each cylinder 113 is provided with a radial passageway 114 opening by a port 115 through the sleeve 53.

The ports 115 are in alignment with the slots 67 and 69 of the shaft 56 as it rotates. The slot 69 has a longitudinal length opening constantly into the chamber 106.

Pistons 116 are slidingly carried one in each of the body cylinders 110, and like pistons 117 are slidingly carried one in each of the block cylinders 113. Opposite pistons 116 and 117 are integrally interconnected and have an annular V-groove 118 therebetween. The shaft cam 68 rides within this groove 118 and thus, upon rotation of the shaft 56, the pistons 116 and 117 are longitudinally reciprocated in their respective cylinders. Incidentally, the pistons are rotated on their individual axes by action of the inclined cam rubbing under driving pressure on a side wall of the groove 118. The pistons 116 and 117 are preferably hollow as indicated in FIG. 2 to reduce their weight otherwise present in solid pistons. The form of the cam 60 is shown in FIGS. 2 and 8 which will reciprocate the pistons each one complete travel from one limit of travel position in one direction to the opposite limit of travel position and then back to the one limit position in one revolution of the shaft 56, the pistons at no time being free of driving connection with the cam 69. The number of such reciprocations may be stepped up by using a cam such as the cam 119 shown in FIGS. 13 and 14 where there are a plurality of peaks 1213 around the cam.

Operations From the foregoing description of the invention it is seen that the invention involves a double end axially reciprocating piston purnp. The description relates to the pump alone. The inlet 102 will be connected to a supply or reservoir (not shown) of oil or other selected fluid. The discharge 80a will be connected to the device (not shown) which is to be actuated or controlled by the pump by a substantially constant pressure with a volume of the fluid variably delivered by the pump in accordance with the need such as would be required in following a piston in a cylinder of the actuated device without loss of pressure moving the piston, all as is well known to those versed in the art, and therefore, such an activated device need not be shown since the invention resides per se in the pump.

The shaft 56 will be connected at its right hand end as viewed in FIG. 2 with a suitable source of power (not shown) which source will, in the present illustration of the one form of the invention, rotate the shaft in a clockwise direction looking from the drive end, FIG. 2.

Assuming that the shaft 5'6 is started to turn, and the movable parts are positioned as indicated in FIG. 2, the port sleeve 71 is positioned by the spring 77 to its extreme right hand position abutting the cam hub 59. The extreme right and left hand Zones 121 and 122 are respectively at the top and bottom sides of the cam 61 Thus the pairs of pistons 116, 117 are positioned in their respective cylinders from the lower extreme left hand limit of travel to the upper extreme right hand limit of travel with the other pairs of pistons regularly spaced in various degrees between those extreme positions.

The pistons 116, 117, FIG. 2, have just completed their left hand travel. In so doing, piston 116 has pushed fluid out of the cylinder 110, forcing the fluid through the passageway 111 and the port 112 to within the sleeve 49, where the fluid encounters the port sleeve 71.

This port sleeve 71, illustrated in longitudinal section in FIG. 2, and developed in FIG. 12A, and in side elevation in consecutive rotated positions in FIGS. -12, has the encircling collar 74 as before described, reciprocal within the bore 41 in the nature of a piston therein. There is a land 123 extending to the right of the collar 74 and circumferentially around the sleeve approximately 180 degrees. This land 123 has a radius of curvature substantially equal to that of the internal wall of the sleeve 49. The longitudinal length of the land equals the distance from the collar 74 to the edge of the port 112, terminating at an arcuate line 123a. There is an arcuate, recessed portion 124 extending around the shaft 56 between the land 123 and longitudinal edges 125 and 126.

A helical land 127 of a transverse width a few thousandths of an inch Wider than the diameter of the port 112 extends in a generally clockwise direction from one end at the juncture of the land lines 123aand 125 in sliding contact with the sleeve 49, spirally around the port sleeve 71 to merge by its other end into an end circumferential land 128 at approximately 180 degrees around the sleeve. This land 128, a complete annular collar, is in sliding contact with the sleeve 49.

A second helical land 129 of the same width as that of the land 127 spirals clockwise around the sleeve 71 from one end leaving the junction of the land lines 123 and 126 in sliding contact with the sleeve 49 and merges by its other end into the collar 128 approximately 180 degrees from the edge 126. The recess 124 extends around the sleeve 71 between the left hand side of the land 127 and the right hand side of the land 129.

There is an irregularly diamond-shaped hole 130 through the sleeve 71, defined by the line 123a; opposing right and left hand sides in part of the lands 127 and 129 respectively; and a circumferential line 131 spaced in parallelism with and from the left of the collar 128. There is a length 132 of the sleeve 71 between the line 131 and the collar 128 recessed to the same depth as that of the recess 124. The line 131 terminates by its end removed from the land 129 short of the line 123a and merges around to the left into the side of the land 127.

The valve sleeve 71 axially reciprocates to effect valving as to the sleeve 49, ports 79 and 112 and shaft port 71).

This piston 116 has just completed a compression stroke forcing fluid through the passageways and 111 through the port 112 into the sleeve 49 within the recess 124 of the port sleeve 71 between the land 127 and the collar 74, and into the chamber 79, tending to pressurize it as well as its connecting passageway 78. When fluid pressure is built up in the chamber 79 and passageway 78, this pressure is exerted on the collar 74 tending to urge it to the left against the pressure of the spring 77. Travel of the collar 74 is also resisted in the event pressure on the discharge side of the partition 81 is built up, this pressure in the chamber 80 being set up by pressure on the right hand side of the partition forcing fluid past the otherwise spring-seated valve 82, it being assumed that flow through the discharge nipple 80a is restricted. Normally the pressure on the right hand side of the partition will be slightly higher than on the left hand side due to the small volume of fluid flowing through the slot 82a, and the spring 77 will retain the port sleeve 71 in position along the shaft in a setting for normal operation. The slot 82a in the valve 82 will also permit pressure to be maintained in the chamber 81) when there is no flow from the discharge nipple 80a. When an increased volume of fluid is required, pressure on the partition left hand side tends to drop and thus the port sleeve will shift to. the left to uncover more of the port 70. The port sleeve is circumferentially keyed to the shaft 56 in definite relation to the ports 68 and 7 0.

Going back to the pressure stroke of the piston 116, the shaft 56 .is rotating with the port sleeve partly uncovering the port 70, allowing fluid to enter through the port sleeve hole 130 between the lands 127 and 129. However flow from therebetween to the port 112 is blocked off by the lands 123 and 129 until the hole 130 comes around into registry with the port 112 and the land 123 intervenes between the port 112 and the chamber 79. The cam 61) is pushing the piston 116 to the right on its fluid intake stroke creating a partial vacuum at the port 70 and fluid flows into the cylinder 111) behind the receding piston 11%.

The port sleeve 71 automatically shifts its position along the shaft 56 to meet the fluid delivery requirements at the outlet 30a, delivering a variable volume of fluid while maintaining a substantially constant pressure. This result is accomplished by the port sleeve 71 varying the effective opening of the shaft port 79. The lands 127 and 129, by their angularity in relation to the shaft axis have a timing to control both fluid flow from the shaft port 711 into the stationary port 112, and pressurized flow back through the port 112 along the external side of the shaft through the gap between the ends and 126 of the land 123, all in timed sequence.

There is the pressure relief valve 92, FIG. 2A, provided to permit fluid discharge from the chamber 79 should the fluid pressure therein build up beyond a pre- '7 determined amount, as previously described, the spring 93 being designed to retain the valve 92 seated until that pressure build up occurs.

When the pump is operating at less than full capacity, the piston 116, moving to the left pushes pressurized fluid through the port 112 along the external side of the gap between the ends 125 and 126 of the land 123 of the port sleeve. Before the piston 116 has reached the limit of its travel, the land 127 passes across the port 112 and the remaining fluid is pushed into the port 13% and thence through the port 71 thus returning the unused fluid to the intake. The piston 116 then moving to the right draws fluid into the cylinder 11% through the port 70 and the port 1311. Before the piston 116 has reached its limit of movement in that direction, the land 129 passes across the port 112 and pressurized fluid is then drawn into the cylinder through the port 112 from the external side of the gap between the ends 125 and 126 of the land 123.

So, far, the operation has been described in reference to the piston 116. That operation is multiplied sequentially by the succeeding pistons in and around the other eight cylinders, by travel of the cam 60, one revolution of which operates all nine of the pistons in that period from initial fluid intake to final fluid discharge, each through its individual port 112, FIG. 5.

The pistons 117 likewise operate in the same manner, but the fluid flow, both intake and discharge follows a different pattern. These pistons 117 have no variable fluid supply such as is the case with the shaft port 70 but to the contrary receive fluid through the shaft port 68 and available around the shaft slot 67 which is in alignment to register with the fixed ports 115 for a few degrees less than 180 degrees four ports 115 being open at all times to the intake flow as the ports are sequentially embraced within the circumferential length of the slot 67, FIG. 6. The pistons 117 corresponding to these ports 115 are in positions in sequence ranging from starting in intake stroke to completion of that stroke.

As each piston 117 starts its compression or discharge 1 stroke, the slot 69 comes into registry with the ports 115 of those pressure stroke pistons and remains in registry with four of those pressurized ports 115, FIG. 6. From these pressurized ports 115, the fluid flows under pressure through the shaft slot 69, the right hand end of which opens constantly into the chamber 106.

This chamber 106, as previously indicated, has a discharge passageway 107, and 78 leading to the chamber 79. Thus, the chamber 79 receives fluid under pressure from both sets of pistons 116 and 117.

When it may be desired to provide a multiple number such as twice as many of intake-discharge strokes of the pistons 116, 117 per revolution of the shaft 56, the cam 120 of the contour shown, FIGS. 13 and 14, and above described may be employed. Modified forms of shaft I and of port sleeve are required.

The shaft 56 in the modified form is provided with a third port 70a diametrically opposite the port 70 for fluid intake twice each revolution when the pump is operating at less than full capacity, the ports supply fluid for only a portion of the intake travel of the pistons 116, 117. The port sleeve 71 is modified to the form of sleeve 133 shown particularly in FIGS. 17-20.

In the sleeve 133, there remains the collar 74 turning in the bore 41, the spring receiving skirt 75, and the right hand annular end land 128. There are two circumferentially spaced apart lands 134 and 135, each of approximately 90 degrees in extent, with opposing spaced apart longitudinal edges 136 and 137 on one side and opposing longitudinal edges 138 and 139 on the opposite side. There are four lands 140, 141, 142, and 143 spiralling around the sleeve 133 longitudinally spaced one from the other merging by right and left hand ends into the land 128 and lands 134 and 135 respectively. All these lands slidingly fit within the sleeve 49. The lands 8 134 and 135 extend to the right from the collar 74 to lines 144 and 145 respectively, both lines being with a common circle around the sleeve, which lines will be at the left hand edge of the port 112 with the sleeve in its extreme right hand position.

The spiral land 1411 leaves the corner portion within the juncture of the edge 136 and the line 144 of the land 134 and extends clockwise around approximately degrees to merge with the land 128. The land 141 leaves the corner portion within the juncture of the edge 137 and the line 144 of the land and extends clockwise around approximately 90 degrees to merge with the land 128. The land 142 leaves the corner portion within the junc ture of the edge 138 and the line 144 of the land 134 to extend approximately 90 degrees around the sleeve and merge with the land 128. The land 143 leaves the portion within the juncture of the edge 139 and the line 145 of the land 135 to extend approximately 90 degrees around the sleeve 133 and merge with the land 128.

The sleeve 133 is recessed between the land edges 126 and 137 and this recess 146 continues around the sleeve between the lands 140 and 141 to the land 128 without communication through to the land 128 without communication through the shaft 56, but does give communication thereover and around from the port 112 to the chamber 79 in timed sequence as the sleeve rotates. The sleeve 133 is also recessed between the land edges 138 and 139, which recess 147 continues around the sleeve 133 between the lands 142 and 143 without opening to the shaft 56. There is an opening 148 to the shaft 56 through the sleeve 133 adjacent and along the land 134 and between the lands 141) and 142, which opening 148 extends in effect to the land 128, excepting for a portion 149 constituting a ledge along the land against the shaft 56 extending along the land 12?, FIG. 18, to the land 142 for riding over the shaft ports 70 and 70a upon left hand shifting of the sleeve 133 along the shaft 56 to limit to a predetermined degree the flow of fluid from the ports 70 and 70a upon beyond full uncovering thereof by the lands 134 and 135 and their intervening recesses 146 and 157. The fluid flow will be as above described in reference to the port 70.

Likewise there is a hole 150 through the sleeve to the shaft 56 adjacent and along the line 145 and extending to and between the lands to the edge of a ledge 151 adjacent the shaft 56 and along and extending to the left of the land 128 to the land 141, FIG. 16, for the same purpose as indicated of the ledge 149.

As in the first form, the ports 112 are sequentially covered and uncovered by four spiral lands 140-143 in varying timed relation as the sleeve 133 may shift longitudinally to meet varying fluid volume flows.

Modified Form 0 Pump The pump heretofore described is entirely satisfactory in its operation. This pump, however, may be shortened and reduced in weight to be in a modified or variant form without departing from the spirit of the invention. This reduction in size is of importance to meet the present situation where space is at a premium under the hoods of modern automotive vehicles.

This modified form is described as follows, referring particularly to FIGS. 22-35.

A body 152 is formed to be generally cylindrical with an offset left hand end portion 153 as viewed in FIG. 22. A pair of left and right hand cylindrical blocks 154 and 155 are fitted within a cylindrical bore 156 in the body 152, the block 154 abutting the end 157, and the block 155 abutting the block 154 in the plane indicated by the line 158. The opposing ends of the blocks 154 and 155 are counterbored to define a chamber 159 therebetween. A passageway 160 leads from the chamber 159 across the block 154 to open through the left end of the block at the bore end 157.

The blocks 154 and 155 and the end portion 153 have 8 a coaxial bore 161 extending entirely therethrough. A sleeve 162 is fixed in that part of the bore 161 in the block 155 and extends preferably to the right slightly outside of the block. The left end of the sleeve 162 terminates at the cavity 159. A sleeve 163 extends from the left side of the cavity 159 through the bore 161 to an annular chamber 165 extending radially of the bore 161. From the left side of the chamber 165, a sleeve 166 extends in the bore 161 to the left end of the portion 153.

A drive shaft 167 is fitted to extend through these sleeves 162, 163 and 166. An enlarged diameter length 168 has a close running fit in the sleeve 162 and extends to the right therefrom through a right hand body mount ing cap 169, in which is carried a radial and end thrust bearing 170 and through which, a reduced diameter length 171 of the shaft 167 extends into an externally protruding driving end 172. The left hand end 173 of the shaft 167 carries a bushing 174 slidingly fitted in the sleeve 166 and fixed to the shaft 167 by any suitable means such as by a pin 175.

On the shaft 167 at the left of the portion 168 is a cam 60 on a hub 176, both within the chamber 159. The shaft 167 has a port hole 177 therethrough opening from a longitudinal bore 178 extending from an axial opening at the left end 173 through the shaft to a zone 179. There is an opening 180 through the shaft 167 at this zone 179, the port 177 and this hole 180 being longitudinally aligned one with the other. The shaft 167 is slotted to extend circumferentially around from this hole 180 to form a parallel sided, radial slot 181, the outer circumferential ends of which are approximately 180 degrees apart.

The two blocks 154 and 155 have a plurality of axially aligned cylinders 182 and 183 respectively, nine in each block, equally circumferentially spaced apart, and axes thereof parallel to the axis of the shaft 167. Double ended piston members 184 have opposite piston end portions 185 and 186 slidingly fitted respectively in the cylinders 182 and 183. An annular V-groove 187 extends centrally around the piston members 184 dividing it into the end pistons 185 and 186. The cam 60 drivingly enters this groove 187 in each case to reciprocate the members 184 upon turning of the shaft 167.

Each cylinder 182 has a radial passageway 188 with a port 189 through the sleeve 163. Each cylinder 183 has a radial passageway 190 opening through a port 191 into the sleeve 162 near the right hand end thereof. All of the ports 191 are in alignment with the groove 181. The side of the shaft 167, 180 degrees from the side shown in FIG. 22, has a circumferential slot 192 extending therearound in alignment with the slot 181 but separated therefrom by the lands 193 and 194, FIGS. 34 and 35. There is a tapering passageway 195 leading by a wide end from the slot 192 to a narrow end abutting a side of the hub 176 and opening thereby into the chamber 159.

A port sleeve 196 is longitudinally slidably carried on the shaft 167 to the left of the hub 176, FIG. 22. This sleeve 196 is held against circumferential turning about the shaft 167 by any suitable means, herein shown as an example, as consisting of a pair of circumferentially spaced apart dogs 197 and 198, FIGS. 31-33, extending from the left end of the port sleeve 196 along and in radially spaced relation from the shaft to enter longitudinally slidably between driving dogs 199 and 200, whereby the two pairs of dogs may permit longitudinal shifting of the port sleeve 196. A compression spring 201 surrounding the shaft 167 enters between these pairs of dogs to abut respectively by ends against the bushing 174 and the port sleeve 196 normally urging the sleeve 196 against the hub 176.

The port sleeve 196 shown in FIGS. 22, 29, 31-33 has a land 202 extending continuously and circumferentially around the sleeve 196 with its periphery in close running contact with the interior of the sleeve 163. A narrow 10 land 203 having a width substantially equal to the diameter of the ports 189, extends from the right side of the land 202 spirally around the sleeve 196 for approximately degrees and merges into an end 204 of a land 205 which extends approximately 180 degrees circumferentially of the right end portion of the sleeve. A second land 206 spirals in width equal to that of land 203, around the sleeve 196 from the right side of the land 202 with equal longitudinal spacing throughout from the land 203 for approximately 180 degrees and merges into the opposite end 207 of the land 205.

The port sleeve 196 has a hole 208 therethrough which passes across the shaft port 177 various distances in accordance with sleeve longitudinal travel. This hole 208 extends to right side of the land 202 and around the sleeve between the spiral lands 203 and 206. The land 205 closes off the space between those lands 203 and 206 at their right hand ends so that fluid flow along the sleeve 196 is stopped thereby. The lands 203, 205 and 206 are in close running contact with the sleeve 163. There is a recess defined by a floor 209 extending between the land 202, the lands 203 and 206 to the right hand end between the land 205 ends 204 and 207, thereby providing fluid travel spirally around the sleeve 196 from the land 202 to discharge from the sleeve at the right hand end.

Operation of Modified Form Referring to the invention form of FIGS. 22-35, the shaft 167 is turning clockwise (viewed from right hand end). The piston is starting to move to the right creating a partial vacuum at the port 189 inducing fluid flow from the shaft 167 bore 178, through the shaft port 177, through the port sleeve hole 208 and through the port 188 to the piston 185. At the same time the piston 186 is traveling to the right forcing fluid out the port 191 into the shaft slot 192, through the passageway into the chamber 159. This action continues in sequence around the bank of pistons 185 and 186. Also, as the cam 60 brings these pistons 135 and 186 each back to a position indicated in FIG. 22, the return travel of piston 185 to the left will force fluid out the port 189 and the port sleeve will have turned with the shaft 167 to receive this fluid from the port 189 between the lands 203 and 206 having the floor 209 therebetween and direct that fluid flow into the chamber 159 for further pres surizing it. Simultaneously with this left hand travel of the piston 185, the piston 186 is likewise traveling to the left creating a partial vacuum at the port 191 and the shaft 167 is in that position when the slot 181 is over the port 191 whereby fluid flow is induced from the shaft bore 178, through the hole 180, through the port 191, and into the cylinder 183. This action is repeated in sequence for all the other pistons 186 as the cam 60 reciprocates them.

The body portion 152 has a passageway 210 opening from the passageway 160 and discharging around the stem 211 extending from a discharge valve 212. The valve 212 has a small, longitudinal slot 212a thereacross to permit a slow pressure interchange between the chambers 210 and 216, serving as explained above in reference to the valve 82 to maintain normally a slightly higher pressure on the right hand side of the partition than on the left hand side due to the small volume of fluid flowing through the longitudinal passageway. This valve 212 is normally seated by a spring 213 against a port 214. The spring 213 extends through a discharge passageway 221 from abutment against the cap 161 into a stem 215 extending from the opposite side of the valve 212 freely into the passageway 214 tending to maintain the valve 212 in a seated condition.

Fluid pressure building up in the passageway 210 will eventually be such that it will move the valve 212 to overcome the spring 213 somewhat to allow fluid to flow past the valve 212 into a discharge chamber 216, across which the valve stem 215 extends. Normally; the fluid under pressure flows from this chamber 216 out the discharge nipple 217. The chamber 216 is in communication with the annular chamber 165, and by a hole 218 through one or more of the dogs 1%, 2%, fluid pressure is communicated to the left hand end of the port sleeve 196.

The port sleeve 196 is shifted along the shaft 167 by difference in fluid pressures of the chambers 159 and 165, compressing or relieving the spring 201 pressure as the situation may be. In this manner, fluid volume control is had by the extent the sleeve covers and uncovers the shaft port 177, all in the manner as above described in reference to the first form.

A relief valve 219 is provided to prevent fluid pressure from increasing beyond a predetermined amount. A passageway 22% leads from the passageway 169 to around a valve 219. This valve 219 is normally held seated against a discharge port 222 by a spring 223 pushing against a collar 224 on a guide stern 225. Too high a pressure will move the collar 224 to the right, FIG. 23, to unseat the valve 219 and allow fluid to flow therepast into a passageway 226 in the cap 161 leading to the fluid intake 227, PEG. 23. Drainage of fluid past the valve stem 215 of the valve 212 will flow from the passageway 221 into the end cap passageway 238, and back to the fluid intake 227, FIG. 22. Also a longitudinal bore 211a through the stern 2H, valve 212, and stem 215 opening to the passageway 238, prevents build up of pressure in the bore 211!) back of the stem 211.

It will be noted, FIG. 26, that the passageway 169 has a considerable volume extending around the cylinder block 154. The combined volumes of the chamber 159 and passageway lull presents a rather large reservoir of fluid under pressure, which tends to smooth out pressure variations in fluid delivery through the nipple 217.

Thorough sealing and holding of parts against the pressure developed of around 2,000 pounds per square inch is of course necessary and of course may vary in design. While not forming a part of the invention per se, two forms are illustrated. In FIG. 2, the end cap 105 is bolted on to the body 49 and abuts the cylinder 56 with sealing rings 228 therebetween. In the form illustrated in FIG. 22, a bayonet type ring 223 revolubly fits around the right end portion of the cylinder block 155 with lands 230 engaging under undercut lands 231 on the body 152, effectively retaining the block in the body. Sealing rings are used such as the ring 232 between the block and the body, and rings 233 and 234 at other possible leak locations.

Therefore it is to be seen that I have presented as my invention a compact pump structure wherein the pump has an automatically variable volume delivery under a constant pressure of high degree. I do not desire to be limited to the precise forms herein shown beyond the limitations as may be imposed by the following claims, since variations may be employed within the skill of the art within the spirit of the invention.

I claim:

1. A pump for delivery of a fluid at substantially constant high pressure and variable volume comprising a body;

a drive shaft rotatably carried by the body;

a plurality of cylinders in one group carried by the body and having their axes circumferentially spaced around and in parallelism with the axis of said shaft;

a piston reciprocally carried in each cylinder;

cam drive means engaging said pistons and actuated by turning of said shaft effecting reciprocation f the pistons;

said shaft having a fluid intake passageway therein with an outlet port on the side of the shaft;

a port sleeve longitudinally slidable along the shaft and fixed on the shaft against circumferential travel therearound;

a cylindrical wall in said body within which said port sleeve revolves and slides in contact therewith;

each of said cylinders having a passageway leading therefrom to a port in said wall, the ports being spaced apart around a common circumferential line;

a fluid receiving chamber at one end of said cylindrical wall and spaced from said cylinder ports;

said port sleeve having a hole therethrough over said shaft port and sequentially registrable with said cylinder ports;

lands helically around said port sleeve sequentially covering and uncovering said cylinder ports by turning of said shaft;

a pair of said lands defining a discharge passageway from the cylinder ports to said receiving chamber;

a fluid discharge chamber; and

a valve between said receiving and said discharge chambers opening under predetermined pressure differential between the receiving and discharge chambers for fluid flow from the receiving chamber into the discharge chamber;

said port sleeve being subject to pressure in said receiving chamber tending to shift the sleeve along said shaft thereby varying the timing of the port sleeve lands in travel across said shaft and cylinder ports for greater fluid flow, and being subject also to pressure in said discharge chamber tending to shift the sleeve in reverse direction along the shaft to reversely vary said timing for less fluid flow.

2. The structure of claim 1 in which there is spring means normally retaining said port sleeve in a position of less than full registration of the shaft port and the sleeve hole; and

spring means yieldingly seating said valve.

3. The structure of claim 1 in which there is a second group of cylinders longitudinally spaced from said first group, one each coaxially aligned with a cylinder of the first group;

each of said pistons extending into an opposing cylinder of the second group;

said cam means engaging said pistons between said two groups of cylinders;

said shaft having a second fluid outlet port spaced along the shaft from said first port;

each of said second cylinders having a passageway leading therefrom with a port registering sequentially with said shaft second port; and

said shaft having a passageway therealong on a side opposite said second outlet port and leading to said receiving chamber.

4. The structure of claim 3 in which said pistons each has an annular groove therearound between said two groups of cylinders;

said cam drive means comprises a rib around said shaft and having peaks spaced apart longitudinally of the shaft; and

said rib fits rotatably into said grooves.

5. The structure of claim 3 in which said cam drive means is located within said receiving chamber.

6. The structure of claim 1 in which one of said lands on said port sleeve extends radially in contact with and between said wall and said shaft extending longitudinally thereof and approximately degrees therearound terminating by ends between which fluid may flow to said receiving chamber, and at all times removed from covering said cylinder ports;

one of each of the pair of lands merging with an end of the 180 degree land; and said pair of lands extend each helically from said 180 degree land around the port sleeve approximately 180 degrees to the opposite sleeve end; and

each of said helical lands having a width sufiicient to cover said cylinder ports; the spiralling of these pairs of lands providing closing and opening of the cylinder ports throughout any longitudinal shifting of the port sleeve.

7. The structure of claim 1 in which there is relief bleeding means of fluid from said discharge chamber at predetermined pressures therein.

8. The structure of claim 1 in which there is a collar around said port sleeve between said receiving and discharge chambers;

said collar serving in the nature of a piston therebetween for subjection on each side thereof the respective chamber pressures for the sleeve longitudinal travel control.

References Cited in the file of this patent UNITED STATES PATENTS Allison June 5, 1917 Dudley July 8, 1941 Beeh Aug. 20, 1946 Jakobsen Nov. 6, 1951 Capsek May 15, 1956 Hoffer Feb. 16, 1960 

1. A PUMP FOR DELIVERY OF A FLUID AT SUBSTANTIALLY CONSTANT HIGH PRESSURE AND VARIABLE VOLUME COMPRISING A BODY; A DRIVE SHAFT ROTATABLY CARRIED BY THE BODY; A PLURALITY OF CYLINDERS IN ONE GROUP CARRIED BY THE BODY AND HAVING THEIR AXES CIRCUMFERENTIALLY SPACED AROUND AND IN PARALLELISM WITH THE AXIS OF SAID SHAFT; A PISTON RECIPROCALLY CARRIED IN EACH CYLINDER; CAM DRIVE MEANS ENGAGING SAID PISTONS AND ACTUATED BY TURNING OF SAID SHAFT EFFECTING RECIPROCATION OF THE PISTONS; SAID SHAFT HAVING A FLUID INTAKE PASSAGEWAY THEREIN WITH AN OUTLET PORT ON THE SIDE OF THE SHAFT; A PORT SLEEVE LONGITUDINALLY SLIDABLE ALONG THE SHAFT AND FIXED ON THE SHAFT AGAINST CIRCUMFERENTIAL TRAVEL THEREAROUND; A CYLINDRICAL WALL IN SAID BODY WITHIN WHICH SAID PORT SLEEVE REVOLVES AND SLIDES IN CONTACT THEREWITH; EACH OF SAID CYLINDERS HAVING A PASSAGEWAY LEADING THEREFROM TO A PORT IN SAID WALL, THE PORTS BEING SPACED APART AROUND A COMMON CIRCUMFERENTIAL LINE; A FLUID RECEIVING CHAMBER AT ONE END OF SAID CYLINDRICAL WALL AND SPACED FROM SAID CYLINDER PORTS; SAID PORT SLEEVE HAVING A HOLE THERETHROUGH OVER SAID SHAFT PORT AND SEQUENTIALLY REGISTRABLE WITH SAID CYLINDER PORTS; LANDS HELICALLY AROUND SAID PORT SLEEVE SEQUENTIALLY COVERING AND UNCOVERING SAID CYLINDER PORTS BY TURNING OF SAID SHAFT; A PAIR OF SAID LANDS DEFINING A DISCHARGE PASSAGEWAY FROM THE CYLINDER PORTS TO SAID RECEIVING CHAMBER; A FLUID DISCHARGE CHAMBER; AND A VALVE BETWEEN SAID RECEIVING AND SAID DISCHARGE CHAMBERS OPENING UNDER PREDETERMINED PRESSURE DIFFERENTIAL BETWEEN THE RECEIVING AND DISCHARGE CHAMBERS FOR FLUID FLOW FROM THE RECEIVING CHAMBER INTO THE DISCHARGE CHAMBER; SAID PORT SLEEVE BEING SUBJECT TO PRESSURE IN SAID RECEIVING CHAMBER TENDING TO SHIFT THE SLEEVE ALONG SAID SHAFT THEREBY VARYING THE TIMING OF THE PORT SLEEVE LANDS IN TRAVEL ACROSS SAID SHAFT AND CYLINDER PORTS FOR GREATER FLUID FLOW, AND BEING SUBJECT ALSO TO PRESSURE IN SAID DISCHARGE CHAMBER TENDING TO SHIFT THE SLEEVE IN REVERSE DIRECTION ALONG THE SHAFT TO REVERSELY VARY SAID TIMING FOR LESS FLUID FLOW. 